Wall anchor

Abstract

A wall anchor having a socket and a drive pin. A passage within the socket receives the drive pin. Fingers on the leading end of the socket have walls in the path of the pin. The fingers pivot into contact with the back surface of the wall by a cam action of the drive pin against the fingers and slightly spaced from a web in front of the fingers. Ribs on the inner wall of the passage grip the drive pin in a ready position. A head on the socket and barbs on the outer wall hold the socket in another part. The fingers have generally flat faces that are barbed to make maximum contact with the wall surface. The drive pin has a shank at its lead portion and helical threads at its trailing portion with a head on the trailing end. The drive pin can be driven by a hammer through the socket and can be withdrawn by the use of a screwdriver.

What is claimed is: 
     
       1. A wall anchor comprising a molded plastic socket and a pin, the socket comprising a body section having a lead end and a trailing end, a passage through the body section for receiving the pin, a pair of elongated fingers integral with the body section and extending from the lead end of the body section, the fingers having thin wall portions joining them to the body section, the thin wall portions being bendable to act as hinges allowing the fingers to swing between normally closed positions in which the outer extremes of the fingers allow the fingers to fit within a predetermined hole in a building wall and spread positions in which the fingers are pivoted laterally outwardly relative to the body section and will not fit through the hole, the fingers being sufficiently long to enable them to be pivoted by a person's fingers, the socket being molded to position the fingers in the normally closed positions to allow the socket to be inserted into the hole in the wall without requiring an external force squeezing the fingers together, the fingers having transverse walls extending across transverse portions of the passage in the path of the pin whereby projection of the pin beyond the leading end of the body section presses the lead end of the pin against the transverse walls of the fingers in a cam action to pivot the fingers to the spread positions, and a plurality of radially inwardly extending longitudinal ribs on the wall of the passage to grip the pin, the ribs being shaped to maintain pressure in a radial direction against the pin upon insertion and extension of the pin in the passage whereby the socket will support and retain the pin prior to installation of the wall anchor, the combination of the ribs retaining the pin and the fingers normally occupying closed positions enabling the wall anchor including the socket and the pin to be inserted in the hole in the wall by one hand. 
     
     
       2. The wall anchor of claim 1 wherein the body section has a generally round cross-section and the fingers are generally rectangular in cross section with flat outer faces to contact the building wall and with chamfered longitudinal outer corners to enable the fingers to pass through the hole. 
     
     
       3. The wall anchor of claim 2 wherein the fingers have tapered leading ends to facilitate introduction into the predetermined hole. 
     
     
       4. The wall anchor of claim 1 including a plurality of axially spaced rings on the outer surface of the body section adjacent the trailing end thereof. 
     
     
       5. The wall anchor of claim 4 including a head on the trailing end of the body section, the passage extending through the head, a plurality of barbs on the outer surface of the body section equally spaced from the head and located between the head and the rings, the circumscribed diameter of the barbs being less than the diameter of the head and being greater than the diameter of the body section. 
     
     
       6. The wall anchor of claim 5 wherein each barb is defined by a leading face at an angle of less than about 30° to the axis of the socket, and a trailing face at an angle of greater than 60° to the axis of the socket. 
     
     
       7. The wall anchor of claim 1 wherein the transverse walls of the fingers are inclined toward the body section, the pin comprising a shank having a leading end and a trailing end, the leading end terminating generally in a hemisphere to assure contact with the transverse walls and avoid jamming between the fingers, a head on the trailing end allowing it to be driven into the socket, and threads on at least a portion of the shank. 
     
     
       8. The wall anchor of claim 7 including slot means in the head for receiving a screwdriver. 
     
     
       9. The wall anchor of claim 7 wherein the threads are helical and have leading and trailing faces, the leading faces being at angles of less than 45° to the axis of the shank and the trailing faces being at angles of greater than 45° to the axis of the shank. 
     
     
       10. The wall anchor of claim 9 wherein the threads are on about one-half the shank adjacent the trailing end thereof and the remainder of the shank adjacent the leading end thereof is cylindrical. 
     
     
       11. A wall anchor comprising a pin and socket wherein the socket includes a body section with a leading end and a trailing end, a pair of fingers hinged to the trailing end and being pivotable relative to the body section, an annular wall surface defining a passage through the body section for receiving the pin, the fingers having transverse walls extending inwardly from the annular inner wall surface in the path of the pin and cooperable with the pin for pivoting the fingers to laterally extending positions, and a web in the passage between the walls of the fingers and the trailing end, the web being independent of the fingers and joined to the socket and extending inwardly from the inner wall surface for interception by the pin before the pin reaches the transverse walls. 
     
     
       12. The wall anchor of claim 11 including a slit in the web enabling the pin to split the web into two halves pressed against the transverse walls. 
     
     
       13. The wall anchor of claim 11 wherein the web is spaced from the walls of the fingers. 
     
     
       14. The wall anchor of claim 11 including a plurality of ribs formed on the body section projecting axially inwardly of the passage wall, the diameter of the pin being greater than the diameter circumscribed by the inward extensions of the ribs and being less than the diameter of the passage whereby the pin can be manually pressed into the passage and held there by the ribs, the pin having a leading end and a trailing end, a point on the leading end, a generally cylindrical shank portion adjacent the point and terminating intermediate the leading end and the trailing end and being longer than the ribs, and helical threads between the cylindrical shank portion and the trailing end, the maximum diameter of the threads being greater than the diameter of the passage. 
     
     
       15. The wall anchor of claim 14 wherein the threads are defined by leading surfaces at less than 45° to the axis of the pin and trailing surfaces at greater than 45° to the axis of the pin, a head on the trailing end of the pin to facilitate driving the pin with a hammer, and a kerf in the head to receive a screwdriver. 
     
     
       16. The wall anchor of claim 15 wherein the trailing surfaces are at about 90° to the axis of the pin. 
     
     
       17. The wall anchor of claim 11 wherein the walls of the fingers are inclined inwardly and toward the trailing end. 
     
     
       18. The wall anchor of claim 17 wherein the angle of inclination is between about 55 degrees and about 65 degrees to the axis of the passage. 
     
     
       19. The wall anchor of claim 17 wherein the web has portions generally parallel to the walls of the fingers. 
     
     
       20. A wall anchor for mounting a part to a wall wherein the part has a hole in it for receiving the wall anchor, comprising a pin and a plastic socket, the socket having a body section and a finger section, a passage through the body section for receiving the pin, the finger section comprising a pair of fingers, short bendable sections for connecting the respective fingers to a first end of the body section and allowing them to pivot about the body section, the fingers having walls in the path of the passage to pivot the fingers laterally relative to the body section upon engagement between the walls and the pin, a head on a second end of the body section, a retainer means projecting outwardly from and located circumferentially about the body section, the retainer means being spaced from the head and cooperating with the head to define a circumferential retainer section therebetween, the diameter of the retainer section being smaller than the diameter of the hole in the part, the diameter of the head and the circumscribed diameter of the retainer means being greater than the diameter of the hole in the part, whereby the socket can be snapped within the hole in the part and the part can be held in place within the retainer section by the head on one side of the part and the retainer means on the other side of the part. 
     
     
       21. The wall anchor of claim 20 wherein the fingers have flat outer faces and outer longitudinal edges that are chamfered, enabling the fingers to fit through the hole while maximizing contact area between the fingers and the wall when the anchor is mounting the part to the wall. 
     
     
       22. The wall anchor of claim 20 wherein the retainer means comprises a plurality of barbs, each barb having a first surface facing the first end of the body section and a second surface facing the second end of the body section, the first surface being at an angle of less than about 25° to the axis of the body section, the second surface being at an angle of greater than 75° to the axis of the body section. 
     
     
       23. The wall anchor of claim 22 wherein the second surface is at an angle of at least 85° to the axis of the body section.